I dont know 'cool'

我现会背五十音图了， I still keep up my learning of English - but i don't understand why people use 'cool ' like in at this topic:'' Lets take a break, ok? cool? ----- "Cool! '' my stupid mind cannot understand; when i first learnt heard 'cool', i knew understood we can use it describe something as great terrific, or the to mean low temperature.

Cool! is just slang, meaning OK! Great!